The ring sizing used on Daintynine is in US standard.
Use a measuring tape to measure the circumference of your finger, making sure that it is a snug fit. Then use the chart below to get your ring size. If you do not have a measuring tape, use a string and mark the end with a pen. Then measure the length of it on a ruler.
You can also measure the inner diameter of an existing ring that you have with a ruler, and use the chart below to get your ring size. However I will strongly recommend using the measurement of the circumference of your finger as it is usually more accurate.
| Circumference (mm) | Inside Diameter (mm) | US Standard |
| 45.40 | 14.45 | 3.5 |
| 46.68 | 14.90 | 4 |
| 47.94 | 15.26 | 4.5 |
| 49.36 | 15.70 | 5 |
| 50.60 | 16.10 | 5.5 |
| 51.87 | 16.51 | 6 |
| 53.16 | 16.92 | 6.5 |
| 54.51 | 17.35 | 7 |
| 55.76 | 17.75 | 7.5 |
| 57.15 | 18.19 | 8 |
| 58.40 | 18.59 | 8.5 |
| 59.69 | 19.00 | 9 |
| 60.98 | 19.41 | 9.5 |
| 62.27 | 19.82 | 10 |